Meso-anylysis Of Granule Material Under Fluid-solid Coupling

The process of interaction between soil and water is essentially a fluid-solid coupling process between the particles and the liquid water in the granules.It is important to analyze the fluid-solid coupling granules from the meso-scale to the prevention and control of the geological disasters.In this paper,the natural phenomena of fluid coupling with cohesive soil and non-cohesive soil granules were simulated and analysed.The mechanism of natural phenomena was analyzed from the meso-scale,the phenomena of some disasters and the prevention and control measures were simulated and analysed.The research results of this paper are the theoretical basis of geological disaster prevention and engineering construction.The specific work of the paper is as follows:For the viscous granules focus on the study of fluid pressure transmission and influence.Then a fluid-solid coupling model of viscous granules was established and the pressure propagation of Darcy flow was verified under low osmotic pressure.After increasing the osmotic pressure,the granular system was meso-analyzed to study the connection between osmotic pressure and the meso-structure of the granular system.The hydraulic splitting was finally simulated,the connection between water injection pressure and granular microstructure is studied.For the non-cohesive granules,the main interest of fluid coupling is the loss of granules.Based on the simplified Navier-Stokes equation,fluid and non-cohesive granules coupling is established.First,the simulation of the Darcy flow is accomplished,then common problems in the geological and engineering construction such as seepage erosion and piping were simulated.The emergence and development of seepage erosion and piping are analyzed,and the meso-structure evolution of the granular system is studied especially on contact force chains and localizations.The measures taken to prevent disasters were simulated and analysed to get the mechanism of prevention.In this paper,the meso-scale analysis of granules is mainly carried out in two directions.First,the force chain network,displacement field and velocity field formed by the interaction between particles are analyzed,and the transmission characteristics of internal force of granules and the movement law of granules are studied.Second,localization of granules is studied by taking approximate continuous medium mechanics method.Especially,the porosity,stress and strain rate is analyzed to obtain the localization imformation of granules.